Maintenance busy link map marking in a stored program controlled switching system

ABSTRACT

A stored program processor controlled switching system is disclosed wherein links of the switching network are busied for both maintenance and communication purposes. The busy or idle state of a link is recorded in a processor link map. A separate maintenance map records the particular links which are busy for maintenance purposes. When a link is made maintenance busy, a link map work defining a link group containing that link is marked with an index to a maintenance map word which contains information as to which link of the link group is maintenance busy. An audit program periodically checks the link map with the actual communication paths through the network and is directed to the proper maintenance map word so that it can reconcile discrepancies between the link map and the communication paths through the network.

United States Patent Comella n51 3,652,804 51 Mar.28,1972

[54] MAINTENANCE BUSY LINK MAP MARKING IN A STORED PROGRAM CONTROLLED SWITCHING SYSTEM Primary Examiner-Kathleen H. Clalfy Assistant Examiner-Thomas W. Brown Anomey-R. J. Guenther and James Warren Falk 72] Inventor: William K. Comella, Holmdel, NJ. [57] ABSTRACT [73] Assign B l l phfln Ll mflol'l s, In orporat d, A stored program processor controlled switching system is dis- M y Hill. NJ. closed wherein links of the switching network are busied for both maintenance and communication purposes. The busy or [22] Filed 1969 idle state of a link is recorded in a processor link map. A [2|] Appl. No.: 869,122 separate maintenance ma records the particular links which P s are busy for maintenance purposes. When a link is made maintenance busy, as link map work defining a link group contain- :1 '8" "179/18 179/1752 agi g ing that link is marked with an index to a maintenance map I 58] i 2 0 word which contains information as to which link of the link group is maintenance busy. An audit program periodically checks the link map with the actual communication paths [56] Re'erences and through the network and is directed to the proper maintenance map word so that it can reconcile discrepancies UNITED STATES PATENTS between the link map and the communication paths through the network. 3,495,220 2/I 970 Lawson ct al ..240/l72.5

12 Claims, 27 Drawing Figures TO TOLL OFFICE I03 I04 SWITCHING NETWORK m) TD TRUNK N S 04 OUTPULSER lI DIGIT RECEIVER 07 TRUNK I JUNCTOP5 POSITION OPERATOR LINKS I I LINKS L POSITION, (A-LINKS) [B-LINKSI I ICLINKS) m I\ I I MtSC. TONE ATND LINK CONTROLLER SERVCE CC POSITION I BUFFER I05 PROCESSOR TELETYPEWRITER PATENTEnmze I972 SHEET CZDF 21 55552 9; IPEmu w mowww 00mm PKTENTEnmze I972 3. 652.804

SHEET 03 or 21 FIG. 3A T567 TRUNK GRID 0 T52 (axe) TERMINAL/ I I (axe) 7 TJS7 (8X8) may 0 L 7 64A-LINKS/TG 0 /TGO T0 TRUNKS OTHER posmow mos Ts LBX TSI (8K8) 7 l" TJSO T50 (ax T axa B T 0 7 O 7 TRUNK OTLER TERMINALS DOSITION em0s PATENTED MR 2 8 I972 SHEET CU 0F 21 FIG. 3B

8B-LINKS /FROM T60 TO P67 PATENTEDMAR 28 I972 SHEET USUF 21 s R O T C N U J JUNCTORS PATENTEDIIIII28 I972 3. 652.804

SHEET OBUF 21 FIG. 6

ENTRY 0F MAINTENANcE REQUEST ENTRY FRoM TELETYPEwRITER IS A cELL AVAILABLE PRINT FAILURE ANY PREVIOUS REQUESTS ON THIS LINK MAP WORD PRINT N0 THIS PREVIOUS ACTIVATE REQUEST TIIIs CELL sET UP INFO IN TER /TI ADDRESSES 22*; 5% N8ROT- LINK MAP Q RoTATEs NBMMAP-MAINTENANCE MAP PRINT SUCCESS MARK LINK MAP WITH MAINTENANCE ACTIVITY BIT AND POINTER To MAINTENANCE MAP T0 EXECUTIVE CONTROL PROGRAM PATENTEnmze e912 3, 652.804

SHEET 09 0F 2 FIG. 7C

TLN A,BLINK TLN A- LINK AMAP (FIGJIA) AMAP (FIG-HA) FOR A- LINK LOAD FOR A-LINK LOAD MAP ADDRESS. MAP ADDRESS, SET TPMMAP SET TPMMAP FROM FROM FIG. 7A Fse. 7A

BMAP (FIGJIC) CKMPAC (FIG-l2) FOR B-LINK LOAD FOR A-AND c- MAP ADDRESS, LINK,CHECK FOR SET TPMMAP OLD REQUESTS m LINK MAP wono J CKMPAC (FIG. I2) T F FOR A AND C LINK O |G.7B LINK,CHECK FOR OLD REQUESTS IN LINK MAP WORD CKMPB (FIG. l2)

FOR B-LINK, CHECK FOR OLD REQUESTS IN LINK MAP WORD INMPL IFKLB) FOR B-LINK, MARK LINK MAP FiG FIG. FIG.

PATENTEIJRAR2B m2 SHEET 1 0 [IF 21 FIG. 7A

REQUESTS TO REMOVE LINKS FROM SERVICE NO CELLS AVAILABLE CHOOSE AN IDLE CELL LOAD CELLJERO NBMMAP WORD 1 CORRgSPONDING T0 T0 THI CELL,ZERO EXECUTWE STORE c LL IIwEx cONTFIOL IN E REGISTER PROGRAM BRANCH ON KIND OF REQUEST PLN PLN PLN J sw C-LINK B-,C-LINKS CMAPIFIGJIB) LY (PIER?) CMAP (FIG.|IB) I FOR C-LINK LOAD FOR C-LINK LOAD FOR C-LINK LOAD MAP ADDRESS, MAP ADDRESS, MAP ADDRESS, SET TPMMAP SET TPMMAP SET TPMMAP I SWITCH I I LINKACI I LINKPRI TO FIGJC TO FIG-7B TO FIGJC PATENTEDMAR28 1912 3,652,804

SHEET 11UF 21 FIG. 7B

TLN B-LINK PLN B-LINK J SW BMAP (FIG.|IC) AMAP LFIGJIA) FOR B-LINK LOAD FOR A-LINK LOAD MAP ADDRESS, MAP ADDRESS, EL.I .M L B W I I SET TPMMAP FROM FIG.7A

CKMPB (FIG.|2)

FOR B-LINK CKMPSW me. I2) CHECK FOR OLD REQUESTS IN FOR SWITCH- LINK MAP WORD CHECK FOR OLD A REQUESTS IN LINK MAP wono F ROM MA E FIG. 7c w L INMPFNFTG. I3) INMPSW (FIG. l3)

ED R LINK, MARK FOR SWITCH, MARK LINK MAP LINK MAP ACTIVATE CELL SET CAMP- ON FLAG PHI NT SUCCESS TO EXECUTIVE CONTROL PROGRAM PATENTEDHARZBIQYE I 3,652,804

SHEET 13UF 21 RESTORE LINKS TO SERVICE ENTERED ON A REQUEST TO RELEASE A CELL SET RESTORE FLAG DOCL FIG, IO

RESTORE MAP ( ZERO CELL PRINT SUCCESS TO EXECUTIVE CONTROL PROGRAM FIG. IOC

B-LINK ALSO REQUESTED TO FIGTB OR FIGQ YES F E TC H ROTATE AND MAP ADDRESS RESTORE BUSY IDLE THE LINK AND ZERO READ MAP MAINTENANCE BITS To F|G.8 YES OR FIGQ s2 2% .9 NO

BUSY THE LINK IN THE MAP UPDATE CELL LINK STATUS To FIG-8 FIG. /0 OR FIG. 9

E10 IOA FIG. IOB

PATENTEnmze m2 3.652.804

sum 15 0F 21 FIG. /0A

CELL WORK DOCL THIS ROUTINE worms 0N CELL-GOES TO LINK MAP AND ATTEMPTS TO BUSY LINKS WHICH HAVE BEEN REQUESTED BY THE CELL-OR RESTORES THE LINKS TO THE IDLE STATE FETCH ROTATE AND MAP ADRS NO (SWITCH) RESTORE READ MAP YES PATENTEnmzs I972 3.652.804

sum 16 or 21 FIG. I08

BUSY THE LINK IDLE THE LINK AND IN THE MAP ZERO MAINTENANCE I BITS IN LINK MAP UPDATE LINK STATUS IN CELL YES TO no.5 DONE OR FIG. 9

INCREMENT MAP ADDRESS RESTORE IDLE THE LINK AND BUSY ZERO MAINTENANCE BITS IN LINK MAP READ MAP BUSY THE LINK IN THE MAP UPDATE CELL LINK STATUS PAIENTEn MIR 2 8 I972 SHEEI 17 0F 21 F/G. IIC

FOR B-LINKS MAP ADDRESS FOR LINK IS PUT IN NBMPAD +C(F)+I ROTATE IN NBROT C (PHI,

MAINTENANCE MAP IS FORMED IN TPMMAR C(F)=CELL INDEX ADD 64 T0 NZLMAD TO GET START OF B-LINK MAP J I ADD GRID BITS ADRS 0F B-LINK TO N8MPAD+I +C(F) l FORM ROTATE STORE ROTATE IN N8ROT+ I +CLF) FIG.

% FIG. FIG. FIG.

IIA IIB IIC PATENTEnIINIze I972 3, 652.804

SHEEI 18 0F 21 FIG. ///I DEVELOP LINK MAP ADDRESS FOR L NK (AMAP) FOR A-LINKS MAP ADDRESS FOR LINK Is PUT IN NBMPAD cm, ROTATE IN NBROTI-CtF),

MAINTENANCE MAP Is FORMED IN TPMMAP.

C(F)=CELL INDEX ADD PARTIAL GRID AND SWITCH TO NZLMAD ADRS OF AL|NK TO NBMPAD+C(FJ FORM ROTATE STORE ROTATE IN N8ROT+ C(F) I SET UP BIT IN POSITION DETERMINED BY ROTATE I OR IN BIT IN TPMMAP TO FIGJA OR 7B OR 7C PATENTEnmzsmz 3.652.804

MAP ADDRESS FOR LINK IS PUT IN N8MPAD +(F), ROTATE IN N8ROT+C(FJ,

MAINTENANCE MAP IS .FORMED IN TPMMAB C(FJ-CELL INDEX ADD 32 T0 N2LMAD TO GET START OF C-LINK MAP ADD PARTIAL GRID AND SWITCH ADRS 0F C-LINK TO NBMPAD +CIFLJ F0 RM ROTATE 

1. A system including a plurality of circuit elements selectively available for a plurality of service tasks and a certain other task, a first memory area storing prescribed indications representing availability data for said elements, means for reserving one of said elements for said certain other task, a second memory area storing which of said elements are reserved for said certain other task, and means responsive to a certain other task reservation condition of said one element for marking said first memory area with a prescribed indication for said one element and an index of a location in said second memory area storing certain other task reservation data for said one element.
 2. The system of claim 1 further including means responsive to said certain other task reservation condition of said one element for marking said second memory area with an address of a location in said first memory area storing availability data for said one element.
 3. The system of claim 2 further including means comparing service task busy conditions of said circuit elements with said Prescribed indications stored in said first memory area, means responsive to a comparison for recognizing in said first memory area a prescribed indication for an element which is not service task busy, and means responsive to said index and activated by said recognizing means for examining said second memory area to determine a certain other task reservation condition for said element which is not service task busy.
 4. A communications system comprising a plurality of links selectively available for communication paths and maintenance paths, a first memory area storing availability data for said links, audit means periodically comparing busy conditions of said links used for communication paths with stored availability data including means responsive to a comparison for recognizing in said first memory area a busy condition of a link excluded from a communication path, and a second memory area storing which of said links are reserved for maintenance paths, characterized by means responsive to a maintenance reservation condition of one of said links for marking said first memory area with an index of the location in said second memory area storing maintenance reservation data for said one link, and means controlled by said index and activated by said recognizing means for examining said second memory area to determine an actual maintenance reservation condition of said link.
 5. In a telephone switching system having a switching network including a plurality of links for establishing connections among trunk circuits, operator positions, and functional service circuits, a processor for controlling said links for establishing said connections for maintenance and communication services, a scratch pad memory having a link map for recording busy-idle data for said links and a maintenance map for recording reservation data of said links for maintenance services, the invention comprising means for addressing said maintenance map to record maintenance reservation data for prescribed ones of said links, means responsive to said maintenance map addressing for controlling said link map to record busy data for said prescribed links, and means for recording in said link map index data of maintenance map addresses for said prescribed links.
 6. In a telephone system, the invention according to claim 5 wherein said link map comprises a plurality of words corresponding to said links in a predetermined fixed format, said maintenance map includes a plurality of numbered cells each selectively associable with a word of said link map when one of said prescribed links whose busy-idle data is recorded in said word is maintenance reserved, each of said cells recording maintenance reservation data for the prescribed links corresponding to the words associated with said each of said cells, and said index data includes the number of the one of said cells associated with said word.
 7. In a telephone system, the invention according to claim 6 further comprising means responsive to said map addressing for recording in said word of said link map flag data indicative of a maintenance reservation for said prescribed links.
 8. In a telephone system, the invention according to claim 7 further comprising means periodically comparing states of links busy in communication service connections with busy-idle data recorded in said link map, means responsive to a comparison for recognizing in said link map a busy link not in a communication service connection, means activated by said recognizing means for examining said flag data to determine a maintenance reservation condition of a link whose busy-idle data is recorded in said word containing said flag data, and means activated by said examining means and responsive to the presence of said flag data for examining an associated cell in accordance with said index data to determine an actual maintenance reservation condition of said busy link.
 9. In a telephone systeM, the invention according to claim 8 further comprising means responsive to flag data in one of said words for inhibiting maintenance reservations for the links corresponding to said one word.
 10. In a telephone system, the invention according to claim 9 further comprising means responsive to a communication busy condition of one of said links for inhibiting a maintenance reservation for said one link until said one link communication busy condition is terminated.
 11. A method for controlling apparatus to mark a processor memory to indicate a maintenance busy condition of one of a plurality of links in a switching system, wherein said links are controlled by said processor for connection into paths for both communication and maintenance purposes, and said processor memory includes a first area storing availability data for said links and a second area storing maintenance busy data for said links, comprising the apparatus steps of recording in said first area of said memory busy data for said one link, recording in said second area of said memory maintenance busy data for said one link, and recording in said first area of said memory at the location containing busy data for said one link the address in said second area of said memory containing said maintenance busy data for said one link.
 12. The method of claim 11 further comprising the step of recording in said second area of said memory at the location containing said maintenance busy data for said one link the address in said first area of said memory containing said busy data for said one link. 